A Study On The Danxia Landfroms In Xinjiang Basin, Jiangxi Province

The Danxia Landform is a kind of red beds geomorphology that developed abrupt slopes. As a new realm of geomorphology, the Danxia Landform has experienced initial, mold and development stage since the danxia topography present by Cheng Guoda in the late of 1930's, and now it tends to mature. A large number of Danxia Landforms that have been found in and abroad have been researched exploited and as a term of geomorphology, the Danxia Landforms has gone abroad successfully and recognized by the world. However, the studies of Danxia Landform are mainly emphasized on the discovery and exploitation at the present time, some scholars have given some researchers on the genesis of Danxia Landforms, but there are mainly directed to certain distribution regions or points and the studies are scattered, the comparison studies conducted on a whole basin or more long-range area are not systematic and deep-going yet, and the controlling factors of the development of Danxia Landforms are still indefinite.The Xinjiang basin is located in long and narrow valley between the mountain ranges of Wuyi and Huaiyu and its tectonic site properly on the suture where the two plates of Yangtze and Cathaysia collided. It had suffered an evolution history from rift basin to fault basin affected by Movement of Pacific Block since Mesozoic and had deposited a set of lower-gray-and upper-red terrestrial facies fragmentary system. Undergone of Himalayan and Neotectonic Movement after Cretaceous and with effects exogenic geological process, there developed a mount of Danxia Landforms in the basin which is one of typical site of Danxia Landform distributions in China.Basin on interpreting of ETM+ remote sensing data, field researching and examining, 15 assemble distribution regions have been figure out. The Danxia Landforms in different area have different features of remote images, and as a whole, from the margin to central of the basin the developments of Danxia Landforms have showed a regularity change. In the margin of the basin there the remote image is latticed and the grid is denser and the Danxia Landforms are distinguished by hoodoos and peak clusters. While in the middle of the basin along the banks of Xinjiang River, the remote image presents hunk red and the rock is exposed and the Danxia Landforms are characteristic with low little stone peaks with scarce vegetation on top of them. And in the transitional region the image is bar shape and the Danxia Landforms are mainly included stone castle, narrow gorge and stone cliffs.The studies show that the development of Danxia Landforms in xinjiang basin has relation with the position, red beds lithologic characters, structure intensity and water system distribution which have played an important role of restrictive function during the development of Danxia Landform. There essential factors formed the landscape genesis system of Danxia Landforms in Xinjiang basin. In the different position of Xinjiang basin, the different element of genesis system has different characteristics, they acted alone or combined that in different positions there developed different landscape assembly while in the similar positions there developed similar landscape assembly that show they undergo similar evolution.The south margin is relatively the concentrated distribution site of Danxia Landforms. From west to east, sites include Celestial Water Rock, Mt.Yingtianshan, Guifeng, Celestial Castle, Mt. Nine Celestial, and Liusiyan. These areas are exposed very thick bedded rocks including conglomerate, pebbly sandstone and sandstone of Maodian formation of Ganzhou group and Hekou formation of Guifeng group. Owing to located in south margin and influenced by the margin faults, the red beds are not only changed its angle sharply that made its dipped but also cut into bars or blocks that increased its fragmentation degree and accelerated the exogenic geological process. Under the vertical erosion of branches of Xinjiang River including Luqi, Luotang, Fengxi et al., there developed high cliffs and the Danxia Landforms are characteristic with hoodoos and peak clusters with a tilted top. Due to the mutual promotion and combined action of landscape genesis elements, the Danxia Landforms evolved quickly and are in their late mature to early old stage.In north margin of the middle basin, there exposed Lianhe formation of Guifeng Group that included thick bedded of pebbly sandstone, conglomerate and sandstone of fluvial-lacustrine sediments with calcitic or argillaceous cement from Hengfeng to Shangrao. Affected by action of north margin faults, the attitude of stratum has been changed from horizontality to incline with angle up to 45°, and the beds are cut into bars or blocks by derivative joints. Owing to long distance from Xinjiang River, the erosion of river is less weak while the corrosion of the rainfall is more strong, and along the fractures of faults and joints, there rocks have suffered long time corrosion that made it to been grooves or caves. The Danxia Landforms are distinguished by landscape assembly including monoclinal mountain, stone peak, stonewall, stone pillar, stone cliff, stone cave, and the evolution of the landforms are at their early mature stage.In the middle of the basin, there exposed Tangbian formation of Guifeng Group along the banks of Xinjiang River, the rocks are compose of thick or huge thick bedded sandstone and pebbly sandstone with large cross bedding, calcitic cement and graded. Due to locate in the middle of basin, poorly affected by the margin faults, the Xinjiang Rive flowed rugged with strange river geological action and have developed lower cliffs along the banks. In the cutbank there have developed groping stone caves by lateral erosion and corrosion of river that were typical landscape in middle of basin. The top of stone peaks are round. Owing to been in the middle, the endogenic geological process is weak while the exogenic geological process is strange and the evolution was slow, the Landforms is in its infancy to early young stage.Between the margin and middle, there exposed mainly sandstone of the upper of Hekou formation, Tangbian formation and the lower of Lianhe formation. The influence of margin faults is in middle. Except nearly the faults in these area where the attitude of strata are also changed clearly, most red beds changed softly, the branches are lack and the river geological action is weak except nearly the faults or branches. The Landforms are in its young to early mature stage which is characterizes with mesa, narrow valley, stone cliff.As a whole, because elements of landscape genesis system have different feature, the Danxia Landforms developed in different part of Xinjiang basin have undergone different evolution histories that influenced the Danxia Landforms zonal distributed. Contrasting in and abroad show that the Danxia Landforms developed in Xinjiang basin is one of the classic representatives by its full range, typical and marvelous spectacle.